• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.438-442
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• 1996

A model testing method to monitor modal characteristics of a rotating disk, such as the mode and its motion relative to the disk, is presented in this paper. It is shown through measurements that this method can be applied to monitor the vibration characteristics of a rotating disk under operating conditions.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.273-274
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• 2002

In order to evaluate the flying characteristics of slider, the acoustic emission (AE) as well as friction signals are typically utilized. In this work the frequency spectrum analysis is performed using the AE signal obtained during the head/disk interaction such as load/unload mechanism using ramp, impact situation in the presence of a bump on disk surface and other contact phenomena including particle interaction. It was shown that the influence of impact can be characterized effectively in the AE frequency spectrum. As a result of this work, frequency spectrum analysis will be utilized with better understanding for studying the head/disk interface (HDI) characteristics and monitoring the particle interaction in HDI effectively.

• 한국컴퓨터정보학회논문지
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• 제18권2호
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• pp.41-47
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• 2013

본 논문에서는 개방 시스템 기반 가상 자원 모니터링 시스템을 CPU, 메모리, 디스크, 네트워크 부분으로 세분화 하고 각각 모듈화하여 설계 및 구현하였다. 설계한 시스템을 구현하기 위해 Windows, Linux, Xen 운영체제를 이용하였고, 구현 언어로는 C++를 사용하였다. 그리고 시스템의 구조는 기능 업그레이드 및 추가 등의 확장성을 고려하여 가능한 기능별로 모듈화 하여 클라우드 컴퓨팅 환경에서 적용 가능한 클라우드 컴퓨팅 가상 자원 모니터링 시스템을 구현하였다. 본 논문에서 설계 및 구현한 클라우드 컴퓨팅 가상 자원 모니터링 시스템의 동작성 검사를 위해 테스트베드를 구축하여 Xen, ESX 하이퍼바이저 운영체제에서 테스트 한 결과 실시간으로 CPU, 메모리, 디스크, 네트워크 정보를 정상적으로 모니터링 함을 확인 하였다.

• 천문학논총
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• 제13권1호
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• pp.39-54
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• 1998

We have developed solar observational system in the department of Astronomy & Space Sciences of KyungHee University, in order to monitor solar activities and construct solar database for space weather forecasting at maximum of 23rd solar cycle, as well as an solar education and exercise for undergraduate students. Our solar observational system consists of the full disk monitoring system and the regional observation system for H a fine structure. Full disk monitoring system is made of an energy rejection filter, 16cm refractor, video CCD camera and monitor. Monitored data are recorded to VHS video tape and analog output of video CCD can be captured as digital images by the computer with video graphic card. Another system for regional observation of the sun is made of energy rejection filter, 21cm Schmidt-Cassegrain reflector, H a filter with 1.6A pass band width and $375\times242$ CCD camera. We can observe H a fine structure in active regions of solar disk and solar limb, by using this system. We have carried out intense solar observations for a test of our system. It is found that Quality of our H a image is as good as that of solar images provided by Space Environmental Center. In this paper, we introduce the basic characteristics of the KyungHee Solar Observation System and result of our solar observations. We hope that our data should be used for space weather forecasting with domestic data of RRL(Radio Research Laboratory) and SOFT(SOlar Flare Telescope).

• 천문학회보
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• 제44권2호
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• pp.60.3-60.3
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• 2019

Binary systems of a white dwarf showing mass transfer activities are classified into cataclysmic variables and symbiotic stars. In the case of cataclysmic variables, the companion is usually a late type main sequence star filling its Roche lobe, where material is transferred through the inner Lagrangian point to form an accretion disk around the white dwarf. The disk becomes unstable and highly viscous when the surface density exceeds the critical density, leading to dwarf nova outbursts. In contrast, symbiotic stars are wide binary systems having a giant as the mass donor. Some fraction of giant stellar wind is accreted to the white dwarf giving rise to various symbiotic activities. In particular, half of symbiotics show Raman O VI at 6830 and 7088, which are important spectroscopic probe of mass transfer process. Monitoring observations using 1 m class telescopes will produce valuable information regarding the mass loss and mass transfer to white dwarf stars, shedding much light on the last stage of stellar evolution of low and intermediate mass stars.

• KSTLE International Journal
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• 제1권1호
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• pp.29-33
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• 2000

In this study, a methodology is developed and confirmed to find the physical contact between the slider and disc due to the defects of disk during head seeking operation using acoustic emission (AE) signal. The head/disk contact was detected during random and standard seeks, whereas no contact was detected during track fellowing. During standard and random seeks, the torsion mode of slider excitation was observed at 680KHz. Therefore, it is thought that AE technique can be used as an alternative method of the glide test by monitoring existence of the torsional mode of the slider during seek operation or can be used to detect the spacing loss during seeking operation. By appropriately choosing the location of the sensor an order of magnitude increase in the sensitivity for RMS AE signal is observed. Therefore we can find take-off velocity clearly with high signal to noise ratio of AE signal.

• Journal of the Korean Wood Science and Technology
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• 제29권3호
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• pp.21-26
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• 2001

Acquisition of precise information on drying characteristics of wood is indispensable for the improvement of drying schedules and wood quality. Recognition of the exact moisture content at which drying defects such as checks occur during drying with given drying conditions may be essential to reduce drying losses. In this study an image-processing system was combined with a laboratory-scale wood dry kiln for experiments and the surface of tree disk of black locust (Robinia pseudoacacia L.) was monitored to investigate the behavior of check formation over all the drying process. This system showed good potential for improving drying schedules and wood product quality.

• 천문학회보
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• 제44권2호
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• pp.50.2-50.2
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• 2019

We present the results of high-resolution (R ≥ 30,000) optical and near-infrared spectroscopic monitoring observations of a FU Orionis-type object, 2MASS J06593158-0405277. We have monitored 2MASS J06593158-0405277 with the Bohyunsan Optical Echelle Spectrograph (BOES) and the Immersion GRating INfrared Spectrograph (IGRINS) since December 2014. Various features produced by wind, disk, and outflow/jet were detected. The wind features varied over time and disappeared about a year after the outburst occurred. The double-peaked line profiles were detected in the optical and near-infrared, and the line widths decrease with increasing wavelength. The disk features in the optical spectra are fit well with G2-type or G5-type stellar spectra convolved with a disk rotational profile of about 45 km s^-1, which corresponds to a disk radius of about 71 R_⊙for a central mass of 0.75 M_⊙. Disk features in near-infrared spectra are fit well with a K1-type stellar spectrum convolved with a disk rotational profile of about 35 km s^-1, which corresponds to a disk radius of about 117 R_⊙ for a central mass of 0.75 M_⊙. We also detected [S II] and H2 emission lines, which are rarely found in FUors but are usually found in the earlier stage of young stellar objects. Therefore, we suggest that 2MASS J06593158-0405277 is in the relatively earlier part of Class II stage.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.471-473
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• 1986

맥주 제조 공정은 다음과 같이 이루어 진다. 담금공정-발효공정-저장공정-여과공정-제품공정, 이중 발효 및 저장 공정은 미생물이 관여하므로 균체의 생육과 제품 생산과의 관계등이 아주 예민하고 복잡하므르 Computer에 의한 자동 계측 및 제어는 효과적인 공정관리 수단이 되며, 또한 품질 향상과 균일화를 기대 할 수 있다. 이에 발효 및 저장조의 128 채널의 공정치 On-line monitoring, graphic display, disk 저장, 프린터로의 reporting 및 제어를 위한 hardware system 구성과 software를 개발하였다.

• 인터넷정보학회논문지
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• 제4권6호
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• pp.13-24
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• 2003

그리드 기술은 지리적으로 분산된 컴퓨팅 자원을 활용하기에 다양한 자원에 대한 정보를 관리하는 기술이 필요하며, 이는 자원 관리 시스템에서 자원을 모니터링하여 이루어진다. 자원 상태 정보가 실시간으로 변하여 주기적으로 모니터링을 해야 하므로 이에 따른 오버헤드가 예상된다. 본 논문에서는 CPU상태 변화 정도를 관찰하여 시스템 상태를 파악하고 이를 모니터링 주기에 적용시키고자 한다. 즉 그리드 환경의 중요한 요소인 자원의 상태를 고려하여 자율적으로 자원의 상태에 따른 모니터링 주기를 조절하는 시스템을 모델링 하였다. 자원의 CPU 상태를 관찰해 CPU의 상태 변화율에 따라 자원의 상태 변화를 파악하여 모니터링 주기를 조절함으로써 모니터링에 의한 오버헤드가 감소하였음을 실험을 통해 증명하였다.